Device for gently removing tissue from animal or human tissue

ABSTRACT

Disclosed is a device for the non-invasive removal of tissue from animal or human tissue, which device has a hollow needle that is provided with a hollow channel. 
     The invention is distinguished by the hollow needle being designed as a multi-wall hollow needle and being provided with at least two hollow needle walls enclosing at least one intermediate space which is designed open at the distal end, by a cutting wire suppliable with electric energy extending at the distal end from the intermediate space, by a supply line being provided for the material flow at the proximal end in the intermediate space of the multi-wall hollow needle and the intermediate space and the supply line being designed in such a manner that the material flow flows through the intermediate space and exits at the distal end, and by a vacuum source being connectable at the proximal end of the hollow channel of the multi-wall hollow needle.

TECHNICAL FIELD

The present invention relates to a device for the minimal-invasiveremoval of tissue from animal or human tissue, which device has a hollowneedle provided with a hollow channel.

State of the Art

There are numerous known different methods and devices employed toexamine tissue for the selective removal of tissue from animal or humanbodies. Starting with the familiar classical surgical procedure using ascalpel to provide a passage to the to-be-severed and to-be-examinedtissue area in order to sever this tissue area with selective cuts andto remove it from the body through the work passage, one proceeded, dueto the many drawbacks related to this classical surgical procedure, todesign a suited instrument for minimal-invasive surgery. Although, it ispossible to extract sufficiently large amounts of tissue material fromthe body for examination with the classical method, the surgery and therelated tissue sections involve irreversible tissue irritation, whichtakes much time to heal. Moreover, there is the danger of celldisplacement in that tissue that may be tumorous is severed and removedthrough the work passage is carried to nonmalignant tissue.

In order to rule out the drawbacks described above, punch biopsy devicesare known which permit removing tissue at selected intracorporal tissueareas by means of a single incision with a needle. This comprises acombination of a hollow needle having a mandrel running inside thehollow needle. This mandrel is provided with a recess at the distal endin which tissue, that can be severed with the aid of the sharpeneddistal end of the hollow needle, can be stored. Although this type oftissue removal is minimal-invasive and involves only minor tissueirritation caused by the injection of the needle arrangement into thebody and the needle arrangement largely rules out the problem of celldisplacement because the tissue severed in the to-be-examined tissue isenclosed in order to be safely removed from the body. The disadvantageof the known punch biopsy, however, is that only a small amount oftissue can be removed with a single incision of the hollow needle.Although the amount of the to-be-examined tissue can be increased bymultiple successive biopsies, the tissue is greatly stressed andirritated by the numerous incisions. On the other hand, hollow needlearrangements with increasingly larger cross sections can be resorted to,however, this raises the danger of bleeding and consequently hematomaformation leading to unavoidable side effects.

DESCRIPTION OF THE INVENTION

The object of the present invention is to design a device forminimal-invasive removal of tissue from animal or human tissue, whichdevice has a hollow needle provided with a hollow channel, in such amanner that the afore-described drawbacks can largely be prevented. Inparticular, the aim is to reduce to a minimum irreversible tissueirritation caused by the surgical operation by means of aminimal-invasive surgical procedure in the to-be-examined tissue area.Injury to the tissue cells from the surgical procedure should also beminimized and the danger of bleeding should be reduced to a minimum.Despite the minimal-invasive surgical procedure, it should still bepossible to remove from inside the body a minimum amount of tissuematerial required for unequivocal determination of the tissuerespectively examination of the tissue.

The solution to the object of the present invention is given in claim 1.Advantageous features that further develop the inventive idea are thesubject matter of the subclaims and are disclosed in the description aswell as in the preferred embodiment with reference to the accompanyingdrawing.

An element of the present invention is to design a device forminimal-invasive removal of tissue from animal or human tissue, whichhas a hollow needle provided with a hollow channel, in such a mannerthat the hollow needle is designed as a multi-wall hollow needle and isprovided with at least two hollow needle walls enclosing at least oneintermediate space which is designed open at the distal end. Extendingat the distal end from this intermediate space is a cutting wire thatcan be supplied with electric energy and is preferably designed with ashape corresponding to the contour of the cross section of theintermediate space and is located at a distance opposite thisintermediate space. A supply line for a material flow ends in theproximal end of the intermediate space of the multi-wall hollow needle,with the supply line and the intermediate space being connected anddesigned in such a manner that that the material flow flows through theintermediate space and exits at the distal end. Preferably anelectrically nonconductive scavenging fluid, for example a glycolsolution, is employed as the material flow. Moreover, the scavengingfluid should possess approximately the same mineral content as the humanor animal tissue fluid or at least be chemically inert so that theintracorporal scavenging has no negative influence on the mineralcontent of the surrounding tissue.

Gases, for instance inert gases such as argon can also be used. Finallya vacuum source can be connected at the proximal end of the hollowchannel of the preferably double-walled multi-wall hollow needle.

The multi-wall hollow needle preferably designed as a double-walledhollow cylinder is preferably provided with an exterior contour matchingthe interior contour of a hollow channel designed as a sluice serving asthe work channel for intracorporal insertion of endosurgical instrumentsinto the body, thus also for insertion of the invented hollow needle. Tokeep tissue and cell irritation to a minimum when inserting such a typeof sluice, for example, through the various layers of the skin down tothe to-be-examined tissue area, there are known sluice arrangementswhich are provided with a helical screw thread on their exterior and atapering-to-a-tip screw thread at the distal end, with the screw tipbeing the distal end part of a mandrel extending through the sluice,which is led through for the purpose of entering the sluice arrangementinside the body. Such a type of sluice arrangement is described in DE199 35 976.8. The particular advantage of such a type of sluicearrangement is that the tissue is not cut when the sluice arrangement isinserted, but rather is dilated by the spiral-like designed tip so thatnatural interfaces in the tissue respectively in the cell structuresentered by the distal screw tip give way thus permitting to largelyavoid severing blood vessels, nerves or cells. Positioning such a sluicecan be controlled using ultrasonic, X-ray or MR monitoring methods tocheck the position relative to the to-be-examined tissue area.

If the sluice arrangement is positioned accordingly and the centralmandrel is removed from the hollow channel, a work channel is createdthrough which the invented tissue removal device can be placedaccordingly. Fundamentally, leading the invented tissue removal devicedescribed in the following through other work channels or the workchannel can even be completely obviated. This however is connected withdistinct drawbacks during the surgical operation. For selective tissueremoval, the multi-wall hollow needle is preferably double walled anddesigned as a hollow cylinder whose needle length is selected largerthan the length of the sluice so that the multi-wall hollow needleextends out of the sluice at the distal end and can enter theto-be-examined tissue area accordingly. Entry of the distal end of themulti-wall hollow needle occurring into the tissue area isdistinguished, in particular, by the cutting wire, which is disposedimmediately before the open distal end of the intermediate space of themulti-wall hollow needle and whose shape essentially corresponds to thatof the cross section of the intermediate space and is positioned at aslight distance therefrom, having electric energy, preferably HFcurrent, applied to it and being heated thereby. The tissue coming intocontact with the cutting wire is thermally severed and simultaneously acoagulation process sets in which prevents later bleeding. So to say thepurpose of the cutting wire is a sort of high-frequency surgical cuttingdevice which immediately protects the cell tissues from bleeding furtherduring severing by means of thermal coagulation. Severing of theto-be-severed tissue can also occur by means of an erosion method, i.e.the tissue does not come into immediate contact with the cutting wirebut rather is thermally denatured by the sparks discharged by the highelectric voltages at the cutting wire. The sparks cause a plasma to formwhich leads to the desired erosion effects. Also feasible is athree-walled design of the multi-wall hollow needle, which contains twointermediate spaces, through one of which a scavenging fluid is led andthrough the other of which a gas is led at the distal end, whichcontributes to the selective plasma formation.

As a result of the distal advancing of the multi-wall hollow needle, thecutting wire, which is preferably designed like a sort of full circle,severs a tissue volume and conveys it into the hollow needle, which hasthe shape of a full cylinder. In order for the tissue severed from theother tissue to be able to completely enter into the interior of themulti-wall hollow needle, the hollow channel of the multi-wall hollowneedle is connected to a vacuum source, by means of which all severedtissue areas are able to enter the interior of the multi-wall hollowneedle. Moreover, a material flow, preferably a glycol solution, whichis supplied to the hollow needle at the proximal end via a supply lineexits from the distal end of the intermediate space. The glycol solutionis able to considerably support the severing process and removal of thesevered tissue areas into the inside of the hollow channel. Furthermore,the glycol solution ensures the desired cooling of the tissuesurrounding the heated cutting wire, whereby minimizing the heat inputon the surrounding tissue is minimized.

In addition to the circular design of the cutting wire, it is providedwith a cutting wire bridge which is directed to the middle of the hollowchannel surrounded by the multi-wall designed hollow needle. Wheninserting the cutting wire ring attached to the distal end of themulti-wall hollow needle into the tissue, the tissue is cut open by thecutting wire bridge in longitudinal direction to the severed tissuecylinder at least half of the severed cylinder diameter. If a desiredincision depth is reached inside the tissue by corresponding insertionof the multi-wall hollow needle into the tissue area, the multi-wallhollow needle including the cutting wire arrangement is turned about thelongitudinal axis of the hollow needle. As a result, the cutting wirebridge severs the tissue core located inside the multi-wall hollowneedle completely on the distal side from the remaining tissue. Thetissue sample severed from the remaining tissue inside the body in thismanner is kept inside the hollow channel by means of the vacuum and canbe easily removed from inside the body through the work channel of thesluice.

In order for the tissue sample completely severed inside the body not tobe uncontrollably sucked away at the proximal end by the vacuum insideof the hollow channel of the multi-wall hollow needle, the vacuum sourceis connected to a single-walled hollow needle at whose distal end ameshwork or a similarly designed arrangement is provided so that onlypredominantly fluid parts or gas parts can be aspired through the hollowneedle at the distal end of the single-walled hollow needle and severedsolid material parts such as the tissue sample itself are kept in frontof the hollow needle at the distal end by the meshwork. For thispurpose, during the cutting process, the hollow needle is inserted atthe proximal end into the hollow channel of the double-walled multi-wallhollow needle. The depth of entry of the single-walled hollow needleinto the double-walled multi-wall hollow needle is selected in such amanner that there is sufficient distance between the distal end of thedouble-walled multi-wall hollow needle and the distal end of thesingle-walled hollow needle connected to the vacuum source so that asufficient amount of tissue material can be drawn inside the hollowchannel. In order to avoid cell displacement through healthy tissueareas, it is advantageous if the reception volume of the hollow channelof the double-walled multi-wall hollow needle is larger than the actualremoved tissue volume. The vacuum inside the hollow channel holds theremoved sample of tissue fast on the single-walled hollow needle therebypermitting removal of the single-walled hollow needle with the tissuecore located at the distal end of the hollow needle.

If a second removal of tissue is required at another site in the tissue,renewed removal can be carried out using the thermal cutting device bychanging the angle of the sluice.

If one replaces the sluice, which as previously described is designedwith an exterior screw thread, with a hollow needle which is providedwith a recess at the distal end, for example in the form of a cut outsection extending halfway to the axis of the hollow channel, repeatedtissue removal in the radial surrounding of the hollow needle ispossible without moving the sluice respectively the work channel,thereby permitting further reduction of possible irritations. Thisoccurs in such a manner that the multi-wall hollow needle is pushed intothe suitable prepared hollow needle maximally to the proximal edge ofthe cut out section. A vacuum applied inside the multi-wall hollowneedle ensures that the tissue material, which lies radially adjacent tothe distal end of the hollow needle immediately opposite the cut outsection, is drawn laterally into the hollow needle. Subsequently themulti-wall hollow needle is pushed toward the distal end with the heatedcutting wire and the tissue material drawn into the cut out section issevered and is conveyed outside the body by means of the previouslydescribed method. This tissue severing procedure can be repeatedaccordingly after the hollow needle is slightly turned about itslongitudinal axis. Turning the hollow needle occurs without any tissueirritation.

With the afore-described method, large pieces of tissue volume can beremoved from the body piecemeal. The removal procedure occurs preferablyunder visual monitoring, for example by means of X-ray observation, sothat selected tissue areas about the hollow needle arrangement can beremoved in a minimal invasive manner.

In order to supply the cutting wire emerging from the distal end of thedouble-walled hollow channel with electric energy, the cutting wire isconnected via an electric connection running at the proximal end insidethe intermediate space. The electric connection runs at the proximal endvia the supply line through which the intermediate space is suppliedwith glycol solution. As both the scavenging fluid and the electric leadrun through one and the same intermediate space, it is absolutelynecessary that the scavenging fluid is not electrically conductive.Corresponding variation of the cutting current, which is supplied to thecutting wire like a HF current, permits selective coagulation at thecutting site, which denatures the tissue and in this way prevents laterbleeding as well as cell displacement.

After successful removal of tissue, the sluice acting as the workchannel can be removed. The essentially dilated tissue assumes itsoriginal position again and can quickly heal.

A particular advantage for subsequent tissue analysis is the partiallongitudinal section inside the tissue sample, severed as a fullcylinder, due to the cutting-wire bridge, because the longitudinalsection permits as a marking aid later unequivocal allocation to theoriginal location in the to-be-examined tissue area before cutting.

BRIEF DESCRIPTION OF THE INVENTION

The present invention is made more apparent in the following without theintention of limiting the scope or spirit of the general inventive ideausing preferred embodiments with reference to the accompanying drawingby way of illustration.

FIGS. 1a to f show diagrams of the individual components for tissueremoval.

FIG. 1a shows a greatly simplified diagram of a sluice hollow needle 1provided with a helical exterior screw thread which is completely filledby a mandrel 2, depicted in FIG. 1b, for insertion into, for example,the layers of skin of a human body. At its distal tip, the mandrel 2 isprovided with a conically tapering screw thread 3 which permitsnon-invasive dilating and insertion of the sluice 1 into anintracorporal area. The hollow needle arrangements shown in FIGS. 1a and1 b are described in detail in DE 199 35 976.8.

When the sluice 1 is correctly positioned with the distal open end at ato-be-examined tissue area, the double-walled multi-wall hollow needle 4according to FIG. 1c is inserted into the sluice 1. The distal end areaof the hollow needle 4 is shown in detail in FIG. 1e. Thecylinder-shaped multi-wall hollow needle 4 is provided with an interiorwall 42 and exterior wall 41 which enclose an intermediate space 43(shown hatched in FIG. 1e). A circular cutting wire 44 which is providedwith a cutting wire bridge extending to the middle of the hollow channelof the multi-wall hollow needle 4 extends from the intermediate space 43which is designed with an open distal end. In order to electricallycontact the cutting wire 44 and the cutting wire bridge 45, the cuttingwire 44 and the cutting wire bridge 45 are connected to an electric leadwhich runs through the intermediate space 43 at the proximal end.

At the proximal side, the double-walled multi-wall hollow needle 4 isconnected to a tube-like supply line 5 which ends with one end in theintermediate space 43 and with its other end, it is connected to anadapter piece 6 which is provided with two connection areas 7, 8. Viathe connection area 7, a glycol solution is fed into the supply line 5through which the glycol solution enters the intermediate space 43 andexits at the distal end area of the hollow needle 4. The electric leadwhich ends in the connection area 8 in order to be connected there to acorresponding HF energy source also runs via the supply line 5.

The multi-wall hollow needle 4 is designed open at both the distal endand the proximal end so that a single-walled hollow needle 9 can beinserted into the multi-wall hollow needle 4 from the proximal end. Thehollow needle 9 is connected to a vacuum source 12, which is not shownin detail. The distal end of the hollow needle 9 is provided with ameshwork 10 as shown in FIG. 1e. Meshwork 10 prevents the tissuematerial sucked into the multi-wall hollow needle 4 from also escapingthrough the hollow needle 9.

The arrangement of the double-walled multi-wall hollow needle 4 and thesingle-walled hollow needle 9 depicted in FIG. 1e shows the state withthe single-walled hollow needle 9 completely inserted into thedouble-walled multi-wall hollow needle 4. Sufficient room is providedinside the multi-wall hollow needle 4 to convey severed tissue materialinto the multi-wall hollow needle 4.

Finally the hollow needle 9 connected to the vacuum source 12 isprovided with a sliding switch 11 with which the vacuum inside thehollow needle 9 can be quickly reduced, which is necessary in order toeasily remove the severed tissue sample removed from hollow needle 4from the distal end of the hollow needle 9.

FIG. 1f shows an additional hollow needle 13 which is provided with acut out section 14 at the distal end. This cut out section extends overhalf the circumference of the hollow needle and has a length l ofapproximately 1-2 cm. The hollow needle is utilized when additionaltissue material which lies radially adjacent to the hollow needlearrangement is to be removed. The hollow needle 13 is provided with alength in such a manner that at the distal end, the hollow needleextends at least with its cut section 14 beyond sluice 1. At theproximal end, the hollow needle 13 is provided with a mechanical stop 16which limits the maximum insertion depth of the hollow needle 13 intothe sluice.

In FIG. 1e, the multi-wall hollow needle 4 is completely inserted in thehollow needle 13. A section through the hollow needle arrangementshowing the hollow needle inside the multi-wall needle 4 is drawn inonly for better depiction. Sluice 1 is not shown in FIG. 1e.

A distance ring 15 which is provided at the hollow needle 9 ensures amechanical stop to the proximal end of the multi-wall hollow needle 4and is provided with a distance ring thickness in such a manner that thehollow needle 9 reaches maximally to the proximal end of the cut outsection 14, because in this manner it is ensured that the severed tissuecan be drawn completely into the multi-wall hollow needle 4 over thelength l. The distance ring 15 can also be removed from the hollowneedle 9 permitting the hollow needle 9 to penetrate deeper into themulti-wall hollow needle 4. This is particularly advantageous if lesstissue volume is to be removed than if the distance ring 15 is provided.

Removal of tissue with the aid of the hollow needle 13 occurs in thefollowing manner. After hollow needle 13 with the multi-wall hollowneedle 4 located inside it has been brought into a respective tissuearea, the tissue area is severed in the longitudinal direction to thelength of the hollow needle either by means of the hollow needlearrangement and removed outside the body or at least it is dilated. Nowthe tissue area extending radially about the distal end region of thehollow needle arrangement has to be removed in a minimal invasivemanner. For this purpose, the multi-wall hollow needle 4 is pushedtoward the proximal end in such a manner that the cut out section 14 isfree. The tissue lying adjacent to the cut out section 14 is drawn intothe hollow needle 13 by the vacuum through hollow needle 9, which islocated inside the multi-wall hollow needle 4. Subsequently themulti-wall hollow needle is pushed toward the distal end and the cuttingwire severs the tissue drawn into the hollow needle 13. The severedtissue is drawn into the multi-wall hollow needle 4. Then the tissue isremoved outside the body accordingly.

The tissue severing process is now repeated after the hollow needle 13is turned preferably a quarter turn in longitudinal direction to theaxis of the hollow needle.

In this manner, the tissue lying radially around the hollow needlearrangement can be removed in a non-invasive manner without permanentlydamaging the surrounding tissue.

LIST OF REFERENCE NUMBERS

1 Sluice

2 Mandrel

3 Screw thread

4 Multi-wall hollow needle

42 Interior wall

41 Exterior wall

43 Intermediate space

44 Cutting wire

45 Cutting wire bridge

46 Electric lead

5 Supply line

6 Adapter piece

7,8 Connection areas

9 Hollow needle

10 Meshwork

11 Sliding switch

12 Vacuum source

13 Hollow needle

14 Cut out section

15 Distance ring

What is claimed is:
 1. A device for the non-invasive removal of tissuefrom animal or human tissue, comprising: a hollow needle with a hollowchannel, wherein the hollow needle is as a multi-wall hollow needle andhas at least two hollow needle walls enclosing at least one intermediatespace which is open at a distal end; a cutting wire, suppliable withelectrical energy and extending at the distal end from the intermediatespace; a supply line provided for the material flow at the proximal endin said intermediate space of said multi-wall hollow needle, saidintermediate space and said supply line providing the material flowthrough the intermediate space and an exiting of the material flow atthe distal end; and a vacuum source connectable at the proximal end ofsaid hollow channel of said multi-wall hollow needle.
 2. The deviceaccording to claim 1, wherein: the cutting wire is suppliable withelectrical energy via an electrical connection which runs through saidintermediate space in a proximal direction.
 3. The device according toclaim 2, wherein: at the proximal end, the electrical connection runsthrough the supply line through which said material flow is conveyableinto the intermediate space and is connected to an electrical energysource.
 4. The device according to claim 1, wherein: the cutting wireextending from the distal end of the intermediate space has a shapematched to a shape of a cross section of the intermediate space.
 5. Thedevice according to claim 1, wherein said cutting wire has a cuttingwire section which extends from said intermediate space into the hollowchannel.
 6. The device according to claim 1, wherein: the multi-wallhollow needle has a circular cross section and the intermediate spacehas a ring-shaped cross section.
 7. The device according to claim 6,wherein: the cutting wire extending from the intermediate space iscircular-shaped and a cutting wire bridge is directed from thecircular-shaped cutting wire to a middle of the hollow channel.
 8. Thedevice according to claim 1, wherein: the vacuum source is connected toa single-walled hollow needle which is provided with an exteriordiameter corresponding to an interior diameter of the hollow channel ofthe multi-wall hollow needle.
 9. The device according to claim 8,wherein: a meshwork is provided at the distal end of the single-walledhollow needle connected to the vacuum source to provide thatpredominantly fluid and gas parts are aspirable and that solid partsremain at the distal end of the hollow needle.
 10. The device accordingto claim 8, wherein: a ventilation device is provided on thesingle-walled hollow needle to reduce the vacuum prevailing inside thehollow needle.
 11. The device according to claim 1, wherein: thematerial flow comprises a fluid.
 12. The device according to claim 1,wherein: the multi-wall hollow needle is provided with an exterior shapematching an interior shape of a work channel which is insertable intolayers of tissue in order to guide the multi-wall hollow needleintracorporally to a to-be-severed area of tissue.
 13. The deviceaccording to claim 1, wherein: a hollow needle is provided into whichthe multi-wall hollow needle is insertable and at the distal end thereofa cut out section is provided.
 14. The device according to claim 12,wherein: the cut out section is a cut out section in a wall of thehollow needle extending over half of a circumference edge of the hollowneedle.
 15. The device according to claim 2, wherein: the cutting wireextending from the distal end of the intermediate space has a shapematched to a shape of a cross section of the intermediate space.
 16. Thedevice according to claim 2, wherein: the cutting wire has a cuttingwire section which extends from the intermediate space into the hollowchannel.
 17. The device according to claim 2, wherein: the multi-wallhollow needle has a circular cross section and the intermediate spacehas a ring-shaped cross section.
 18. The device according to claim 2,wherein: the cutting wire extending from the intermediate space iscircular-shaped and a cutting wire bridge is directed from thecircular-shaped cutting wire to a middle of the hollow channel.
 19. Thedevice according to claim 8, wherein: a ventilation device is providedon the single-walled hollow needle to reduce the vacuum prevailinginside said hollow needle.
 20. The device according to claim 2, wherein:the material flow comprises a fluid.
 21. The device according to claim2, wherein: at the proximal end, the electrical connection runs throughthe supply line, through which the material flow is conveyed into theintermediate space, and is connected to an electrical energy source. 22.The device according to claim 3, wherein: the cutting wire extendingfrom the distal end of the intermediate space has a shape matched to ashape of a cross section of the intermediate space.